Fast-dispersing dosage forms which are designed to release the active ingredient in the oral cavity are well known and can be used to deliver a wide range of drugs. Many such fast-dispersing dosage forms utilize gelatin as a carrier. Gelatin B. P., which is normally utilized in such formulations, is defined as a protein obtained by partial hydrolysis of animal collagenous tissues such as skin, tendons, ligaments and bones, with boiling water. However, such mammalian derived gelatin has an unpleasant taste and thus necessitates the use of sweeteners and flavors in such fast-dispersing dosage forms to mask the taste of the gelatin in addition to any sweeteners and flavors which may be required to mask the taste of the active ingredient. Moreover, when conventional mammalian derived gelatin is used in the production of such fast-dispersing dosage forms, it is necessary to heat the gelatin solution to 60° C. in order to effect solution. This heating step increases processing times and incurs heating costs thereby increasing the overall costs of the process.
U.S. Pat. No. 5,120,549 to Gole et al. discloses a fast-dispersing matrix system which is prepared by first solidifying a matrix-forming system dispersed in a first solvent and subsequently contacting the solidified matrix with a second solvent that is substantially miscible with the first solvent at a temperature lower than the solidification point of the first solvent, the matrix forming elements and active ingredient being substantially insoluble in the second solvent, whereby the first solvent is substantially removed resulting in a fast-dispersing matrix.
U.S. Pat. No. 5,079,018 to Ecanow discloses a fast-dispersing dosage form which comprises a porous skeletal structure of a water soluble, hydratable gel or foam forming material that has been hydrated with water, rigidified in the hydrated state with a rigidifying agent and dehydrated with a liquid organic solvent at a temperature of about 0° C. or below to leave spaces in the place of the hydration liquid.
Published International Application No. WO 93/12769 (PCT/JP93/01631) describes fast-dispersing dosage forms of very low density formed by gelling, with agar, aqueous systems containing the matrix-forming elements and active ingredient, and then removing water by forced air or vacuum drying.
U.S. Pat. No. 5,298,261 to Pebley et al. discloses fast-dispersing dosage forms which comprise a partially collapsed matrix network that has been vacuum dried above the collapse temperature of the matrix. However, the matrix is preferably at least partially dried below the equilibrium freezing point of the matrix.
Published International Application No. WO 91/04757 (PCT/US90/05206) discloses fast-dispersing dosage forms which contain an effervescent disintegration agent designed to effervesce on contact with saliva to provide rapid disintegration of the dosage form and dispersion of the active ingredient in the oral cavity.
U.S. Pat. No. 5,595,761 to Allen Jr. et al. discloses a particulate support matrix for use in making a rapidly dissolving tablet, comprising a first polypeptide component having a net charge when in solution, e.g. non-hydrolyzed gelatin; a second polypeptide component having a net charge of the same sign as the net charge of the first polypeptide component when in solution e.g. hydrolyzed gelatin; and a bulking agent, and wherein the first polypeptide component and the second polypeptide component together comprise about 2% to 20% by weight of the particulate support matrix and wherein the bulking agent comprises about 60% to 96% by weight of the particulate support matrix; and wherein the second polypeptide component has a solubility in aqueous solution greater than that of the first polypeptide component and wherein the mass to mass ratio of the first polypeptide component to the second polypeptide component is from about 2:1 to about 1:14; and wherein when the support matrix is introduced into an aqueous environment the support matrix disintegrates within less than about 20 seconds.
EP 0 690 747 B1 to Nguyen et al. describes particles comprising an excipient forming a matrix and at least one active ingredient uniformly distributed in the mass of the matrix which are prepared by a process comprising the steps of preparing a homogenous pasty mixture with a viscosity below 1 Pa·s measured at room temperature (15-20° C.), at least one active ingredient, a physiologically acceptable hydrophilic excipient and water; extruding the resulting homogenous mixture and cutting the extrudate to give moist particles; freezing the resulting particles as they fall under gravity through a stream of inert gas at a temperature below 0° C.; and drying the particles by freeze drying.
Australian Patent No. 666,666 discloses a rapidly disintegratable multiparticulate tablet having a mixture of excipients in which the active substance is present in the form of coated microcrystals or optionally coated microgranules. Such tablets are thought to disintegrate in the mouth in typically less than 60 seconds.
U.S. Pat. No. 5,382,437 to Ecanow discloses a porous carrier material having sufficient rigidity for carrying and administering an active agent which is capable of rapid dissolution by saliva. The porous carrier material of Ecanow is formed by freezing a liquified ammonia solution comprising liquid ammonia, liquid ammonia soluble gel or foam material, and a rigidifying agent for the gel or foam material selected from the group consisting of a monosaccharide, a polysaccharide and combinations thereof, and deammoniating the frozen material thus formed, by causing material transfer of ammonia from the frozen state to the gas state thereby leaving spaces in the carrier material in place of the frozen ammonia.
Published International Application No. WO 93/13758 (PCT/US92/07497) describes tablets of increased physical strength which are prepared by combining and compressing a meltable binder, excipients and a pharmaceutically active agent into a tablet, melting the binder into the tablet and then solidifying the binder. In one embodiment, a disintegrating agent is utilized to increase the disintegration rate of the tablet after oral intake. In another embodiment, a volatizable component is used to form porous tablets. Some embodiments disintegrate in the mouth in less than 10 seconds.
U.S. Pat. No. 3,885,026 to Heinemann et al. and U.S. Pat. No. 4,134,943 to Knitsch et al. also disclose fast-dispersing porous tablets and a method for increasing their physical strength by first compressing the tablet and then volatilizing a readily volatilizable solid adjuvant incorporated in the tablet to attain the desired porosity.
Published International Application No. WO 94/14422 describes a process for drying frozen discrete units in which the solvent is removed under conditions whereby the solvent is evaporated from the solid through the liquid phase to a gas, rather than subliming from a solid to a gas as in lyophilization. This is achieved by vacuum drying at a temperature below the equilibrium freezing point of the composition at which point the solvent (such as water) changes phase.
While the prior art is replete with methods and techniques for the preparation of rapidly dispersing dosage forms, it has failed to consider the benefits associated with the use of fish gelatin, especially non-gelling, non-hydrolyzed fish gelatin, in such dosage forms. The pharmaceutical industry would be able to avoid the use of mammalian derived gelatin due to taste considerations. Thus, there exists the need for improved fast-dispersing dosage forms which are designed to quickly release the active ingredient in the oral cavity that avoid the use of mammalian derived gelatin.